compounds such as alcohols, unsaturated fatty acids, and amines were produced in the cultures cultivated at 1.2 V. These results suggest that application of an electric field changes the structure of the microflora, which promotes extracellular electron transfer and the biodegradation of organic compounds, thus enhancing methane production from coal. Furthermore, the distinct organic products detected after cultivation and the significant changes in microbial communities suggest that the degrading metabolism of organic matter in coal might be altered due to the application of an electric field. Based on the results, a biogenic methane production system implemented by application of an electric field was proposed and described.

Guo, Y., Deng, W., Wei, G., Chen, X., Liu, X., Wang, X., Lo, L., Cai, G., Zeng, T., 2020. Exploring the temperature Porites dependence of clumped isotopes in modern corals. Journal of Geophysical Research: Biogeosciences 125, e2019JG005402.

https://doi.org/10.1029/2019JG005402 Porites corals are valuable geological archives for reconstructing past sea surface temperature (SST) Abstract: in tropical oceans. Their clumped isotope compositions (indicated by Δ values) provide a potential proxy for 47 Porites SST. The Δ value in coral usually departs from thermodynamic equilibrium due to vital effects. To 47 13 18 explore the temperature dependence of Δ values in corals, we determined δ C, δ O, and Δ values in two 47 47 Porites modern corals from the South China Sea. Our results indicate no intercolony or intracolony biases in Δ 47 13 values on annual timescales. However, on seasonal timescales, Δ enrichment associated with δ C depletion is 47 observed at an intracolony level. This cannot be explained by incomplete hydration and/or hydroxylation of metabolic CO ; instead, we interpret this new pattern of isotopic anomalies as a peculiar evidence of vital 2 13 Porites effects on Δ and δ C fractionation. Although complicated by vital effects, the Δ signature in corals 47 47 still preserved a robust SST dependence, similar to those of recently published Δ -T calibrations. The observed 47 Δ offset relative to inorganic carbonate due to the vital effects is consistent, and relative variations in seasonal 47 Porites SST can be obtained. This study refines the Δ thermometer in corals and strengthens its capacity to be 47 used to reconstruct past SST. Sea surface temperature (SST) is a fundamental parameter of climate variation. Plain Language Summary: Language Summary: Understanding how SST has changed in the past is important to inform climate predictions. One way to do this is by developing a reliable thermometer based on the clumped isotope composition (Δ ) of corals. However, 47 the thermometer based on coral Δ values may be complicated by biological factors that affect the Δ values as 47 47 Porites the coral grows. We investigated two modern corals from the South China Sea by measuring their oxygen, carbon, and clumped isotope compositions. By comparing two samples from the same coral colony, we found that the impact of biological factors is significant, causing unusual patterns in the carbon and clumped isotopes. The bi ological factors also likely lead to differences in the coral Δ values from two different 47 colonies. To account for these potential intracolony and intercolony effects, we established a relationship between the Δ values and SST based on the two corals. This relationship has the same temperature 47 dependence as other Δ thermometers established on synthetic carbonates in which no biological factors are 47 involved and can be used as a thermometer to reconstruct seasonal SST.

Guzmán-Trampe, S.M., Ikeda, H., Vinuesa, P., Macías-Rubalcava, M.L., Esquivel, B., Centeno-Leija, S., Tapia- Cabrera, S.M., Mora-Herrera, S.I., Ruiz-Villafán, B., Rodríguez-Sanoja, R., Sanchez, S., 2020. Production of Streptomyces distinct labdane-type diterpenoids using a novel cryptic labdane-like cluster from thermocarboxydus K155. Applied Microbiology and Biotechnology 104, 741-750.

https://doi.org/10.1007/s00253-019-10240-3 Streptomyces thermocarboxydus Bioinformatic mining of the K155 genome predicted the presence of four synthases for the production of geosmin, hopene, albaflavenone, and a type B-type A diterpenoid system like lrd that described for labdane-related diterpenoids (LRD). The cluster was comprised by an operon of four lrdABDC genes ( ). This cluster seemed to be silent in the wild-type strain, as neither labdane nor terpene-like compounds were detected by UPLC-TOF-MS and GC-MS analyses in both culture supernatants and mycelial lrdABDC Streptomyces extracts. Heterologous expression of the cluster in a defective cyslabdan producer ( cyslabdanicus cld K04- 0144Δ ) generated 8,17-epoxy-7-hydroxy labda-12,14-diene and cyslabdan. The same